Biochemistry week 5 Flashcards
(40 cards)
What are eicosanoids derived from
Polyunsaturated fatty acids with 20 carbons, Arachidonic acid
What are eicosanoids produced by
All cells expect redblood cells
What are eicosanoids involved in
- Physiologic response: Inflammation and -pathologic response : hypersensitivity
What are the functions of eicosanoids
Maintain gastric integrity
-Support renal function
-Regulate smooth muscle contraction
Where is Arachidonic stored
In cell membranes
What is arachidonic acid released by
Phospholipase A2
Where can arachidonic acid also be sourced from
- Cholesteryl esters
What is another name for the enzyme activity Cyclooxygenase + what does it require
Prostaglandin G synthase
-Requires 2 oxygen molecules
Name the Isozymes of cyclooxygenase
- COX 1
-COX 2
What is Arachidonic Acid involved in
- Inflammatory stimuli
Give characteristics of COX 1
-When it is present
-Where its found
-What does inhibition increases the risk of
- Constitutive (always present)
-Found in gastric mucosa and renal cells
-Increases the risk of gastric ulcers
Explain COX -2
-Where is it most active
-What it is inhibited by
-Most active in inflamed tissues
-Inhibited by asprin ( irreversible), NSAIDS(reversible) , + seleective COX 2 inhibitors
Give examples of Eicosanoids
- Prostaglandins
-Leukotrienes
-Prostacyclins
-Thrombaxane A2
Name the 2 major pathways for Arachidonic acid metabolism
- 5-lipoxygenase pathway
-Cyclooxygenase patheway
In the 5 lipoxygenase pathway:
-WHAT happens
-What is it inhibited by
- It breakds down Arachidonic acid (AA) to produce 5-HPETE
-Inhibited by zileuton
In the cyclooxygenase pathway what happens
- COX1 +COX 2 breaks down Arachidnoic acid to release Prostaglandin H2
Where is Thromboxane A synthase located + function
- In Endoplasmic Reticulum
-Converst endoperoxide PGH to thromboxane A2
Explain the affetcs of prostaglandinds E1 and Prostaglandinss E2
- Vasodilation
-Increases gastric bicarbonate secretion
-Increases pain sensititivty
Name 2 Analogs
- Alprostadil
-Misoprostol
Explain what is Alprostadil + Misoprostol used for
-Alprostadil- Used in treating pulmonary hypertension
-Misoprostol- Used for Medical Abortion
What does Prostaglandin E2 induce and prevent
- Induces labor
-Prevents NSAIDS-induced gastric ulcers
What does Prostaglandin F2a cause
- Smooth muscle contraction
Name the analog for Prostaglanin F2a + what its used in
- Carboprost
-Medical abortion
What is Thromboxane A2 :
-secreted from
-What does it cause/effect
Secreted from Platelets
-Causes vasoconstricttion + platelet aggregation
